If you just want to provide staff with access to the LAN OR guests (and guest devices) with access to the internet - all from one access point - then a budget AP will do you fine.

For me, I bought sonicpoints because I wanted to use the controller capabilities of the sonicwall device, to have multiple AP's, and to also publish multiple SSID's - one for staff access to the LAN (Using RADIUS/AD) and another for locked down guest access to the internet. All done as simply as possible, and this did the job except I couldnt get it work over a VLAN for some reason and had to patch in some physical links instead.